US MSHA does not issue “approvals” for diesel particulate filters

4 February 2003

The US Mine Safety and Health Administration (MSHA) has expressed concerns about certain diesel particulate filter manufacturers advertising products which have never received any formal approval or certification as “MSHA-Approved”. MSHA has stated that it does not “approve” diesel particulate filters or any other emission control devices.

In its statement, MSHA made a reference to the Program Information Bulletin (PIB) NO. P00-13, Mine Safety and Health Administration Product Approvals, issued back in 2000 to address the concerns about advertising products as “MSHA Approved.” The PIB stated:

“The practice of evaluating products and equipment for suitability for their intended application has caused some confusion in the interpretation of the use of the words “MSHA-Approved.” Some manufacturers have falsely advertised their products and equipment evaluated for suitability as “MSHA-Approved,” suggesting that the Agency endorses the use of a specific product or piece of equipment. Since no specific approval regulations have been established which apply to the evaluation of these products in mining operations, MSHA can not authorize the use of any marking on the product or piece of equipment suggesting that it is “MSHA-Approved” nor advertising it as such.”

The recent concerns are related to the tests of NO2 activity of a number of diesel particulate filters conducted by MSHA in relation to the underground coal mine application. It was found that catalytic filters utilizing active oxidation catalysts, such as platinum at high loadings, increase the NO2 portion of NOx to levels that may cause miners to be exposed to concentrations of NO2 in excess of the legal MSHA exposure limit of 5 ppm. Based on this finding, MSHA stated that “particulate filters introduced into the underground mine (...) must not cause an increase in NO2 concentrations in the raw exhaust” (compare PIB P02-4 and PIB P02-7). However, MSHA has not introduced a diesel particulate filter approval program, nor required that particulate filters must be emission tested by MSHA.

MSHA maintains a list of diesel filter systems, which provides a guideline for the mines. Filters have been divided into two categories: catalyzed, platinum-based filters which have a potential to increase NO2, and other types of filters, which do not increase NO2. MSHA has emphasized that listing in the latter category does not constitute an “approval” or “certification”, but is intended as a guideline for mines which have to comply with both the diesel particulate matter requirements and with the NO2 exposure limit.